Materials for the solid/liquid extraction of heavy metal ions, containing supported N-functionalized polyazacycloalkanes

ABSTRACT

The present invention relates to a material notably adapted for the extraction of metal cations in an aqueous medium, comprising a solid support on which are attached polyazacycloalkane compounds having a ring including at least 4 nitrogen atoms, and wherein the nitrogen atoms of the ring are substituted with coordinating groups, which each are independently:
         a coordinating group of formula:
 
—(CH 2 ) n —C(═O)—NR 1 R 2  
    or else   a both coordinating and binding group, fitting the formula:
 
—(CH 2 ) p —C(═O)—NR 3 -(A)-[support].
       

     The invention also relates to methods for preparing the aforementioned materials and to different uses thereof, notably for the extraction of Pb 2+  cations in an aqueous medium.

This is a 371 of PCT/FR09/050271 filed Feb. 20, 2009, which has apriority of French no. 08 51309 filed Feb. 28, 2008, hereby incorporatedby reference.

The present invention relates to the field of solid/liquid extraction ofmetal cations, and notably of heavy metal cations (in particular lead,cadmium, copper or nickel cations) present in liquid media. Theinvention more specifically relates to the solid materials designedhereafter under the generic term of “extraction materials”, which allowtrapping of metal cations in a liquid medium and their extraction out ofsuch a liquid medium, and which i.a. prove to be particularly welladapted to the extraction of Pb²⁺ cations out of aqueous media. Theinvention also relates to methods for synthesizing such extractingmaterials.

The solid/liquid extraction of heavy metal cations out of liquid media,notably out of aqueous media, is a well-known technique, to which it isoften resorted industrially. As a general rule, such a solid/liquidextraction is conducted by putting the liquid medium to be treated,contaminated by heavy metal cations, in contact with a solid capable ofcomplexing these heavy metal cations, whereby at least one portion ofthe heavy metal cations present in the liquid medium are found trappedby the solid, thereby inducing purification of the liquid medium.Extraction techniques of this type find many practical applications,among which may notably be mentioned the treatment of drinking waterbefore its consumption, or else further the treatment of waste water orindustrial effluents (notably aqueous effluents) before their beingdischarged into the environment.

Many extraction techniques of the aforementioned type have beendeveloped and used for a long time. Within this scope, the use of ionexchange resins has notably been described, capable of binding certainmetal cations, such as for example the chelating resin Amberlyst IRC718®marketed by Rohm & Haas which includes iminidiacetate groups giving itgood affinity for copper and iron cations, or else the GT73® resin basedon a polystyrene matrix modified by sulfur-containing end groups, whichis itself adapted to scavenging copper, silver, cadmium and lead.

More generally, the use of functionalized polymers has beencontemplated, for example of the type of polymeric beads bearingdithiocarbamate groups described in Polyhedron, Vol. 15, pp. 4241-4254(1996) or scavenging materials based on polymers bearing acrylic endgroups of the type of those disclosed in Energy Fuels, Vol. 12, pp.792-797 (1998). It is also known that certain natural materials such aslignin or chitosan have the property of binding certain heavy metals,this capability may further be improved by grafting sequestering groupson this type of materials. On this subject, it is notably possible torefer to Water Res., Vol. 33, pp. 2469-2479 (1999) or to Bull. Chem.Soc. Jpn, Vol. 70, pp. 2446-2447 (1997).

Moreover extracting materials have been proposed based on an inorganicsupport, among which mention may be made of absorbance of cations basedon immobilized ligands on silica gels or mesoporous silicas, of the typeof those described for example in Chem. Commun. pp. 258-259 (2000), J.Chem. Soc, Dalton Trans., pp. 2206-2209 (2001), Science, Vol. 276, pp.923-926 (1997) or Adv. Mater., Vol. 9, pp. 550-503 (1997).

More generally, a large number of methods have been described relying onthe surface modification of organic or mineral supports by groupscoordinating, complexing or sequestering metal cations, the extractionof which is sought. In the sense of the present description, suchcoordinating, complexing or sequestering groups will be designated bythe generic term of “coordinating group”.

Notably taking into account increasingly strict statutory requirementsin terms of public health and discharges into the environment, there istoday a real need for solid/liquid extraction methods allowingparticularly efficient and selective removal of metal cations of theheavy metal cation type within liquid media. Such methods are mostparticularly required in the field of treatment of drinking watersintended for human consumption, where requirements as regards residualheavy metal contents, and notably lead content, are increasing strict.

As an indication, the standard presently in effect in France (set by thedecree No. 2001-1220 as of Dec. 20, 2001 applying the European directive98/83/EC of Nov. 3, 1998) sets at 25 micrograms per liter (i.e. 25 ppb)the maximum admissible lead content in drinking water, and thisthreshold will be 10 micrograms per liter (10 ppb) from Dec. 25, 2013.As regards treatment of waters intended to be consumed, there istherefore a need for extraction methods for lead and possible otherheavy metals until contents as low as a few ppb are obtained, and thispreferably without extracting in the same time other useful speciespresent in drinking water, such as for example alkaline or earthalkaline cations. Methods of this type, allowing efficient extraction ofheavy metals are also of interest for treating waste waters orindustrial aqueous effluents, insofar that the acceptable residual heavymetal contents for effluents discharged into the environment themselvesalso tend to become increasingly low.

A method developed in this direction was notably described in theinternational application WO 01/46202, which relates to extractingmaterials notably intended for extracting Pb²⁺ ions in an aqueousmedium, which comprises a support of the silica gel type, grafted byN-functionalized polyazacycloalkanes. By using these supportedN-functionalized polyazacycloalkanes, it is of course possible to attaingreater purification thresholds than those obtained by using commercialion exchanger resins, but the materials disclosed in this applicationhowever prove to be insufficient, in the most general case for obtainingan extensive purification level of the type required in the treatment ofdrinking water.

An object of the present invention is to provide novel solid extractingmaterials adapted to solid/liquid extraction of metal cations in aliquid medium notably allowing more efficient removal of Pb²⁺ cationsthan that obtained with materials disclosed in the aforementioned WO01/46202. More generally, the invention has the object of providing asolid extracting agent allowing extraction of lead ions and preferablyions of other heavy metals out of a liquid medium (and most particularlyout of an aqueous medium) with sufficient efficiency for meeting thedemands required in the field of purification of drinking waters and oftreatment of industrial effluents and waste waters before theirdischarge in the environment.

In order to achieve these objects, according to a first aspect, thepresent invention provides a material adapted to the extraction of metalcations. This material comprises a solid support (designated hereafterby S) on which are bound in a covalent way polyazacycloalkane compounds(designated hereafter by PACs) having a ring including at least 4nitrogen atoms, and wherein each of the nitrogen atoms of the ring issubstituted with a coordinating group, each of the coordinating groupsborne by the nitrogen atoms of the ring of a PAC bound to the support(S) being independently of each other:

-   -   either a coordinating group, designated hereafter by Rc group,        fitting the following general formula:        —(CH₂)_(n)—C(═O)—NR¹R²        -   wherein:            -   n=1, 2 or 3;            -   R¹ and R² are identical of different and each of them                represents a hydrogen atom or an alkyl radical                comprising 1 to 4 carbon atoms, or an alkenyl radical                comprising 1 to 4 carbon atoms or an aryl radical;    -   or a coordinating and binding group, designated hereafter by RcL        group, fitting the following general formula:        —(CH₂)_(p)—C(═O)—NR³-(A)-[support],        -   wherein:            -   p=1, 2 or 3;            -   R³ represents a hydrogen atom, or an alkyl radical                comprising 1 to 4 carbon atoms, or an alkenyl radical                comprising 1 to 4 carbon atoms, or an aryl radical                (preferably a hydrogen atom or an alkyl radical                comprising 1 to 4 carbon atoms);            -   -(A)- represents a saturated or unsaturated linear or                branched hydrocarbon chain, optionally totally or partly                cyclized and optionally interrupted by one or more                heteroatoms, bound by at least one covalent bond to the                solid support (S).

Thus, an extracting material according to the invention is a materialbased on a solid support (S) modified by covalent grafting ofpolyazacycloalkane compounds (PACs) including 4 or more nitrogen atoms,each of these compounds (PACs) being specifically substituted with acoordinating group (Rc or RcL) as defined above on each of the nitrogenatoms of its ring.

The exact nature of the solid support (S) on which are bound thepolyazacycloalkane compounds (PACs) may vary to a rather wide extent,subject to allowing covalent grafting of the compounds (PACs) on itssurface as required according to the invention. According to a generallyinteresting, although not systematic, embodiment, it is typicallypossible to use as a solid support (S), a solid support comprising amineral oxide, generally at least at its surface.

According to an embodiment which proves to be particularly interesting,the solid support (S) used according to the invention comprises silicagel. According to a specific embodiment generally well adapted to theapplication of the invention, the support (S) used is formed by such asilica gel. Silica gels useful as a support (S) according to the presentinvention, are notably amorphous silica gels of the Kieselgel type ormesostructured silica gels of the MTS type notably described in J. Chem.Soc, Dalton Trans., pp. 1209-1214 (1996) and Chem. Mater., Vol. 13, pp.3151-3168 (2001).

In the sense of the present description, the expression“polyazacycloalkane compound” designates an organic compound including apolyazacycloalkane ring, i.e. a saturated ring of the polyazacycloalkanetype where several of the groups (CH₂) are replaced with secondary ortertiary amine functions (in other words, a polyazacycloalkane ring is acycloalkane chain interrupted by several nitrogen atoms).

The polyazacycloalkane compounds used within the scope de la presentinvention systematically have a ring comprising at least 4 nitrogenatoms, and this number of nitrogen atom most often remains less than orequal to 12, and more preferably less than 8 (typically, this number ofnitrogen atoms is equal to 4, 5 or 6).

The polyazacycloalkane ring of the polyazacycloalkane compounds (PACs)present on the extracting materials of the present invention istypically a cyclic link of 4 to 12 (post often 4 to 8, for example 4, 5or 6) identical or different units of formula —N(CH₂)_(n)—, wherein, ineach of said units, n designates independently an integer comprisedbetween 1 and 4, and more preferably an integer equal to 2 or 3.

According to an advantageous embodiment of the present invention, thepolyazacycloalkane compounds (PACs) present on the extracting materialof the present invention are at least partly (and preferably totally)tetraazacycloalkane compounds, i.e. compounds bearing a ring exactlyincluding 4 nitrogen atoms, this ring being preferably:

-   -   a 1,4,8,11-tetraazacyclotetradecane ring with 14 links, fitting        the following formula:

-   -    or else    -   a 1,4,7,10-tetraazacyclotridecane ring with 13 links, having the        formula below:

Whatever its correct nature, the polyazacycloalkane ring ofpolyazacycloalkane compounds (PACs) present on an extracting materialaccording to the invention is systematically functionalized by an Rc orRcL group of the aforementioned type on each of the nitrogen atoms ofits ring. Each of these Rc and Rcl groups, which have the capacity ofbeing able to complex metal cations, is designated herein by the genericterm of “coordinating group”. The presence of such a group withcoordinating nature at each of the nitrogen atoms of the ring of thepolyazacycloalkane compounds (PACs) is a specificity of the materials ofthe invention which is made possible by the specific preparation methoddeveloped for this purpose within the scope of the present invention andwhich is described in the present description later on.

The work carried out by the inventors within the scope of the presentinvention has now allowed a demonstration that the systematic presenceof coordinating groups on each of the nitrogen atoms of thepolyazacycloalkane ring gives to the materials of the invention veryhigh extraction efficiency for certain metal cations, in particularheavy ion cations such as Pb²⁺, Cd²⁺, Cu²⁺, Zn²⁺ or Ni²⁺. The materialsof the invention prove to be most particularly well adapted forisolating or removing these cations in different liquid media, andnotably in aqueous media, and this both in a static mode and in adynamic mode.

In particular, the materials of the invention prove to be mostparticularly adapted to treatment of drinking water. They notably allowvery efficient removal of Pb²⁺ cations, which proves to be suitable forrather easily reaching the required purification level in the field ofdrinking water. The work of the inventors more specifically gives thepossibility of establishing that the materials of the invention arecapable of ensuring extremely efficient decontamination of an aqueousmedium contaminated by lead, by finally obtaining without any difficultyresidual lead contents of less than 10 micrograms per liter, and thiswhile having the advantage of not retaining alkaline and earth alkalinecations at the same time. Such a performance level may further beobtained, including in a dynamic mode, which opens the possibility ofefficiently using the extracting materials of the invention in purifyingcartridges for drinking water simply placed upstream or downstream froma domestic tap for distributing drinking water. Thus, for example, thework of the inventors has notably shown that an extracting materialaccording to the invention may be efficiently used in order to reducethe concentration of Pb²⁺ cations to a residual content of the order of10 ppb or less for drinkable water conveyed by a lead pipe, and thissimply by means of a suitable purifying cartridge placed at the outletof the water distribution tap (for example a cartridge of the typedescribed in patent JP 02 301469).

Without intending to be bound to a particular theory, the work carriedout by the inventors gives the possibility of putting forward that theexcellent extraction capacities obtained within the scope of theinvention seem to be due to the fact that the polyazacycloalkanecompounds immobilized on the support (S) have a capacity of complexingmetal cations substantially similar to the one they would have if theywere in the free state within a liquid medium. In fact, it seems thatconsidering the specific presence of a coordinating group at each of thenitrogen atoms of their ring, the polyazacycloalkane compoundsimmobilized on the support (S) behave like “molecular claws” capable ofefficiently chelating cations of suitable size, schematically in thesame way as the same compounds present in the free state within a liquidmedium.

In other words, the extracting materials of the invention may, somewhat,be described as an immobilized form of complexing agents of thepolyazacycloalkane type having not lost their complexing efficiencybecause of their covalent grafting on a solid support. It should benoted that the materials of the invention thereby constitute asignificant advance as compared with the polyazacycloalkane compoundsimmobilized on a support, described in the aforementioned application WO01/46202, for which covalent grafting systematically requiresimmobilization of at least one of the nitrogen atoms of thepolyazacycloalkane ring, and which are therefore in fine again foundwithout at least one coordinating group, thereby reducing the efficiencyof the “molecular claw” ensured by the coordinating groups capable ofbeing borne by the nitrogen atoms of the polyazacycloalkane group.

Notably, in order to obtain the highest possible efficiency forcomplexing metal cations for a material according to the invention, mostoften it proves to be preferable to select polyazacycloalkane compoundswherein the coordinating groups remain as free as possible to ensuretheir role of molecular claw able to immobilize a metal cation. For thispurpose, it is generally preferable to limit the number of coordinatinggroups of polyazacycloalkane compounds which are found again immobilizedon the support (S), which, if they were in a too large number, would becapable of leading to stiffening of the ring, potentially detrimental tothe efficiency of complexation of the cations.

In the most general case, it notably proves to be preferable that thecoordinating groups borne by the nitrogen atoms of the ring ofpolyazacycloalkane compounds (PACs) comprise the less possible number ofRcL groups (coordinating and binding groups) fitting the aforementionedformula —(CH₂)_(p)—(═O)—NR³-(A)-[support]. According to a particularlyinteresting embodiment, the coordinating groups formed by the nitrogenatoms of the ring of polyazacycloalkane compounds (PACs) comprise atmost a coordinating and binding group RcL of this type.

According to a first interesting alternative, an extracting materialaccording to the invention may advantageously comprisepolyazacycloalkane compounds (PACs) immobilized on the solid support (S)without any coordinating group bound to the support, i.e.polyazacycloalkane compounds only bearing coordinating groups Rcexcluding any RcL group.

According to this first alternative of the invention, the extractingmaterial preferably comprises polyazacycloalkane compounds (PACs)immobilized on the solid support (S), which fit the following formula(I):

wherein:

-   -   a, b and c are three integers, either identical or different,        each of a, b and c being equal to 2 or 3;    -   d1 and d2 are two integers, either identical or different, equal        to 0, 1 or 2, it being understood that the sum (d1+d2) has the        value 1 or 2;    -   each of the 4 Rc groups, either identical or different (and most        often identical) represent a group fitting the general formula:        —(CH₂)_(n)—C(═O)—NR¹R²    -    as defined above;    -   —(B)— is a saturated or unsaturated linear or branched        hydrocarbon chain, optionally totally or partly cyclized, and        optionally interrupted by one or more heteroatoms, bound by at        least one covalent bond to the solid support (S).

According to this first alternative, it often proves to be advantageousthat all the polyazacycloalkane compounds (PACs) immobilized on thesolid support (S) fit the aforementioned formula (I).

Polyazacycloalkane compounds particularly well adapted to theapplication of the first alternative of the invention are compoundsfitting the formula (I) given above. Moreover, in the compounds offormula (I), it often proves to be interesting that b=3 and (d1+d2)=2,and in that in particular when a=c=2 (the case when b=2 and (d1+d2)=2and the case when b=3 and (d1+d2)=1 may also be considered, inparticular when a=c=2, but they often prove to be less interesting).

An extracting material according to the first alternative of theinvention which generally proves to be particularly suitable as anextracting material, comprises polyazacycloalkane compounds (PACs)immobilized on the solid support (S) fitting the following formula (Ia)(preferably excluding any other polyazacycloalkane compound):

wherein:

-   -   a, b, c, d1, d2, as well as the groups Rc have the meanings        given above for formula (I);    -   —Y— is a saturated or unsaturated linear or branched divalent        hydrocarbon group, optionally totally or partly cyclized and        optionally interrupted by one or more heteroatoms;    -   j is an integer equal to 0, 1, 2 or 3; and    -   k, which represents the number of bonds between the cyclic        species and the solid support (S), is an integer equal to 1, 2        or 3.

According to a particular embodiment of the first alternative of theinvention, the polyazacycloalkane compounds (PAC) immobilized on thesolid support (S) fit one of the formulae below:

wherein k has the aforementioned definition.

According to a second interesting alternative, other than thealternative defined above, an extracting material according to theinvention may comprise polyazacycloalkane compounds (PACs) immobilizedon the solid support (S) via a bond ensured by a both coordinating andbinding group RcL of the aforementioned type. In this particularscenario, it is often preferable that each of the thereby immobilizedpolyazacycloalkane compounds only comprises a single RcL group and thatthe whole of the other coordinating groups are non-binding coordinatinggroups Rc.

According to this second alternative of the invention, the extractingmaterial of the invention preferably comprises polyazacycloalkanecompounds (PACs) immobilized on the solid support (S) which fit thefollowing formula (II):

wherein:

-   -   a, b, c and d are three integers, either identical or different,        each of a, b, c and d being equal to 2 or 3;    -   each of the 3 Rc groups, either identical or different (and most        often identical) represents a group fitting the general formula:        —(CH₂)_(n)—C(═O)—NR¹R²    -    having the aforementioned definition; and    -   p, R³ and -(A)- have the aforementioned definitions.

It often proves to be advantageous, within the scope of this secondalternative, that all the polyazacycloalkane compounds (PACs)immobilized on the solid support (S) fit the aforementioned formula(II).

Polyazacycloalkane compounds particularly well adapted to applying thesecond alternative of the invention are compounds fitting the formula(II) given above, wherein a=c=2. Moreover, in the compounds of formula(II), it often proves to be preferable that b=d=3, and this quitenotably when a=c=2 (the case of b=3 and d=2 and the case of b=2 and d=3may also be considered, notably when a=c=2, but often they do prove tobe less interesting).

An extracting material according to the second alternative of theinvention which generally proves to be particularly well adapted as anextracting material comprises polyazacycloalkane compounds (PACs)immobilized on the solid support (S) fitting the following formula (IIa)(preferably excluding any other polyazacycloalkane compound):

wherein:

-   -   a, b, c, d, p and the groups Rc and R³ have the meanings given        above for formula (II);    -   z is a saturated or unsaturated, linear or branched divalent        hydrocarbon group, optionally totally or partly cyclized (for        example as an aryl group) and optionally interrupted by one or        more heteroatoms (z may for example a divalent alkylene group        containing 1 to 8 carbon atoms, for example 2, 3, 4 or 5 carbon        atoms). According to a specific embodiment, z may comprise a        carbonyl group (for example included in a urea group);    -   j′ is a integer equal to 0, 1, 2 or 3; and    -   k′, which represents the number of bonds in the cyclic species        and the solid support (S), is an integer equal to 1, 2 or 3.

According to a particular embodiment of the second alternative of theinvention, the polyazacycloalkane compounds (PACs) immobilized on thesolid support (S) fit one of the formulae below:

wherein k′ is as defined above.

According to a particular aspect, the object of the present invention isa method giving access to extracting materials as defined above. Thismethod for preparing materials of the invention generally includes thesteps hereafter:

-   (E1) a solid support is provided including at the surface, functions    Fs capable of reacting with complementary functions, said Fc    functions, in order to form a chemical covalent bond;-   (E2) functionalized polyazacycloalkane compounds (PAC^(f)) bearing    an Fc function of the aforementioned type are prepared from    polyazacycloalkane compounds (PAC⁰) having a ring including at least    4 nitrogen atoms,-   by attaching (in one or several steps) a coordinating functional    group on each of the nitrogen atoms of the ring of the    polyazacycloalkane compounds (PAC⁰),    -   wherein each of said coordinating functional groups attached on        the nitrogen atoms of the ring is, independently of the others:        -   a coordinating group Rc fitting the general formula:            —(CH₂)_(n)—C(═O)—NR¹R²        -   wherein n, R¹ and R² have the aforementioned meanings;        -   or        -   a coordinating and reactive group RCr fitting the following            general formula:            —(CH₂)_(p)—C(═O)—NR³—(P)-G¹            -   wherein:                -   p and R³ have the aforementioned meanings;                -   —(P)- represents a chemical bond or else a saturated                    or unsaturated, linear or branched hydrocarbon                    chain, optionally totally or partly cyclized (for                    example as an aryl group) and optionally interrupted                    by one or more heteroatoms, bound through at least                    one covalent bond to the solid support (S); and                -   -G¹ is a functional group bearing a function Fc                    capable of reacting with the functions Fs borne by                    the solid support, provided in step (E1) for forming                    a covalent bond between the polyazacycloalkanes                    (PAC^(f))-   it being understood that, in the case when none of the functional    groups attached on the nitrogen atoms of the ring is a group Rcr,    then the polyazacycloalkanes (PAC^(f)) are further functionalized on    one of the carbon atoms of the ring by a reactive group Rr of    general formula -(Q)-G², wherein:    -   -(Q)- represents a chemical bond or else a saturated or        unsaturated, linear or branched hydrocarbon chain, optionally        totally or partly cyclized (for example as an aryl group) and        optionally interrupted by one or more heteroatoms, bound through        at least one covalent bond to the solid support (S); and    -   -G² is a functional group bearing an Fc function capable of        reacting with the Fs functions borne by the solid support        provided in step (E1) for forming a covalent bond between the        polyazacycloalkanes (PAC^(f)), and-   (E3) the functionalized polyazacycloalkanes (PAC^(f)) obtained in    step (E2) are put into contact with the solid support provided in    step (E1).

The method of the invention applying the steps (E1), (E2) and (E3) abovespecifically applies the reaction of Fs functions borne by the solidsupport provided in step (E1) with complementary Fc functions borne bythe functionalized polyazacycloalkanes (PAC^(f)) prepared in step (E2),these Fc functions may be borne by an Rcr group or by an Rc groupintroduced in step (E2).

The Fs functions borne by the support may be functions inherent to saidsupport (for example —OH functions when the support is a mineral oxidesuch as silica gel) or else functions grafted on said support (functionsof the type —Cl or —NH₂ for example), the step (E1) then comprising apreliminary step for functionalizing this support with Fs groups.

Not as a limitation, the Fs functions borne by the solid supportprovided in step (E1) and the complementary functions Fc borne by thefunctionalized polyazacycloalkanes (PAC^(f)) obtained in the step (E2)may for example be selected from the pairs of functions Fs/Fc below:

-   -   Fs=—OH/Fc=—Si(OR)₃ wherein R is an alkyl group comprising 1 to 4        carbon atoms (typically 1 or 2);    -   Fs=—X/Fc=—NH₂ wherein X is a halogen atom (preferably Cl);    -   Fs=—Si—H/Fc=—CH₂—CH═CH₂;    -   Fs=—Si—H/Fc=-Ph-CH═CH₂ wherein Ph represents an aromatic ring        either substituted or not (for example a benzene ring, either        substituted or not).

An important specificity of the method of the invention is that step(E2) is specifically conducted so that the polyazacycloalkane compounds(PAC^(f)) are functionalized by attaching a coordinating functionalgroup on each of the nitrogen atoms of the ring of thepolyazacycloalkane compounds (PAC⁰). This is ensured in step (E2) byfunctionalizing each of the nitrogen atoms of the polyazacycloalkanering with an Rc or Rcr group of the aforementioned type.

Generally it is preferred that step (E2) be conducted by attaching asless as possible coordinating and reactive functional groups of the Rcrtype, whereby in fine a material is obtained wherein thepolyazacycloalkanes are bearers of a reduced number of coordinating andbinding groups of the RcL type, as defined above in the presentdescription. Thus, according an interesting embodiment of the method ofthe invention, it is preferred that at most one of the coordinatingfunctional groups attached in step (E2) be a coordinating and reactivegroup of the Rcr type of the aforementioned type, whereby in thesynthesized material the coordinating groups borne by the nitrogen atomsof the ring of the polyazacycloalkane compounds (PACs) comprise at mostone coordinating and binding group RcL.

Generally, when in step (E2) a coordinating group or a coordinating andreactive group Rcr are attached on one of the nitrogen atoms of the ringof the polyazacycloalkane compounds (PAC⁰), this group may be grafted ina single or in several steps. Moreover, an Rcr group may be obtained bymodifying a group of Rc type grafted beforehand. Thus, according to aparticular embodiment, the step (E2) of the method of the invention maytypically be conducted by grafting (in one or several steps) acoordinating group Rc on each of the nitrogen atoms of the ring of thepolyazacycloalkane compounds (PAC⁰), and then by introducing an Fcfunction on the thereby obtained modified polyazacycloalkane compounds,this introduction may be carried out either by grafting a group Rc onthe ring and/or by converting one or more of the Rc groups into Rcrgroups (this conversion of an Rc group into an Rcr one is performed byfunctionalizing said group Rc with an Fc function).

According to a particular embodiment adapted for preparing extractingmaterials according to the first alternative of the invention, whereinthe polyazacycloalkane compounds (PACs) do not contain any RcL group,the step (E2) may for example be conducted as follows:

-   -   a coordinating group Rc as defined earlier is attached (in one        or more steps) on each of the nitrogen atoms of the ring of the        polyazacycloalkane compounds (PAC⁰);    -   and, a priori or a posteriori,    -   the polyazacycloalkanes (PAC^(f)) are further functionalized on        one of the carbon atoms of the ring with a reactive group Rr of        formula -(Q)-G² as defined above.

When the method of the invention is intended to provide extractingmaterials bearing polyazacycloalkanes of formula (I) according to thefirst alternative of the invention, the polyazacycloalkane compounds(PAC^(f)) prepared in step (E2) advantageously fit the following generalformula (If):

wherein:

-   -   a, b, c, d1, d2 and Rc have the definitions given above for        formula (I); and    -   Rr is a reactive group of general formula -(Q)-G² having the        aforementioned definition.

According to a first specific embodiment with which extracting materialsbearing polyazacycloalkanes of formula (Ia) according to the firstalternative of the invention may be obtained, the method of theinvention is conducted as follows:

-   -   the solid support provided in step (E1) is a silica gel which        includes its surface —OH functions as Fs functions; and    -   the compounds (PAC^(f)) prepared in step (E2) are compounds        bearing trialkoxysilane functions —Si(OR)₃ as Fc functions,        which fit the following general formula (If-a1):

wherein:

-   -   a, b, c, d1, d2, Rc, —Y— and j are as defined above for formula        (Ia); and    -   R is an alkyl group comprising 1 to 4 (typically 1 or 2) carbon        atoms.

Preferably, according to this first particular embodiment, the compounds(PAC^(f)) prepared in step (E2) fit the following formula (If-a1.1):

wherein:

-   -   a, b, c, d1, d2, Rc, j and R are as defined above for formula        (Ia); and    -   q is an integer of value 1, 2, 3 or 4,        said compounds (If-a1.1) being obtained in step (E2) by applying        the succession of the following steps:

According to a second specific embodiment with which extractingmaterials bearing polyazacycloalkanes of formula (Ia) according to thefirst alternative of the invention may be obtained, the method of theinvention is conducted as follows:

-   -   the solid support provided in step (E1) is a modified silica gel        which includes surface functions —X as Fs functions, wherein X        is a halogen atom (preferably Cl), this modified silica gel        being obtained by grafting a trialkoxysilane of formula        X—(CH₂)_(j)—Si(OR)₃, wherein j is as defined above for formula        (Ia), and R is an alkyl group comprising 1 to 4 (typically 1        or 2) carbon atoms; and    -   the compounds (PAC^(f)) prepared in step (E2) are compounds        bearing —NH₂ functions as Fc functions, which fit the following        general formula (If-a2):

wherein:

-   -   a, b, c, d1, d2, and Rc are as defined above for formula (Ia);        and    -   -Y1- is a saturated or unsaturated, linear or branched divalent        hydrocarbon group, optionally totally or partly cyclized (for        example as an aryl) and optionally interrupted by one or more        heteroatoms.

Preferably, according to this second particular embodiment, thecompounds (PAC^(f)) prepared in step (E2) fit the following formula(If-a2.1):

wherein:

-   -   a, b, c, d1, d2, and Rc are as defined above for formula (Ia);        and    -   r is an integer having the value of 1, 2, 3 or 4,        said compounds (If-a2.1) being obtained in step (E2) applying        the succession of following steps:

wherein Alk is an alkyl group comprising 1 to 4 carbon atoms.

According to a particular embodiment adapted for preparing extractingmaterials according to the second alternative of the invention whereinthe polyazacycloalkane compounds (PACs) contain a single RcL group, thestep (E2) may be conducted as follows:

-   -   a reactive coordinating Rcr group is attached on one of the        nitrogen atoms of the ring of the polyazacycloalkane compounds        (PAC⁰), in one or several steps;    -   and; a priori or a posteriori,    -   coordinating groups Rc are attached as defined earlier on each        of the other nitrogen atoms of the ring of the        polyazacycloalkane compounds (PAC⁰), in one or several steps.

When the method of the invention is intended to provide extractingmaterials bearing polyazacycloalkanes of formula (II) according to thesecond alternative of the invention, the polyazacycloalkane compounds(PAC^(f)) prepared in step (E2) advantageously fit the following generalformula (IIf):

wherein:

-   -   a, b, c, d and Rc are as defined above for formula (II); and    -   Rcr is a coordinating and reactive group fitting the general        formula —(CH₂)_(p)—C(═O)—NR³—(P)-G¹ as defined above.

According to a first specific embodiment with which extracting materialsbearing polyazacycloalkanes of formula (IIa) according to the secondalternative of the invention may be obtained, the method of theinvention is conducted as follows:

-   -   the solid support provided in step (E1) is silica gel, which        includes its surface —OH functions as Fs functions; and    -   the compounds (PAC^(f)) prepared in step (E2) are compounds        bearing trialkoxysilane functions —Si(OR)₃ as Fc functions,        which fit the following general formula (IIf-a1):

wherein:

-   -   a, b, c, d, p, Rc, R³, z and j′ are as defined above for formula        (IIa); and    -   R is an alkyl group comprising 1 to 4 (typically 1 or 2) carbon        atoms.

According to this first particular embodiment, in step (E2), thepreparation of the aforementioned compounds (PAC^(f)) of formula(IIf-a1) may for example apply either one of the reaction schemes below:

wherein X is a halogen atom, preferably Cl;or

wherein p′=1, 2 or 3.

According to a second specific embodiment with which extractingmaterials bearing polyazacycloalkanes of formula (IIa) according to thesecond alternative of the invention may be obtained, the method of theinvention is conducted as follows:

-   -   the solid support provided in step (E1) is a modified silica gel        which includes surface —X functions as Fs functions, wherein X        is a halogen atom (preferably Cl), this modified silica gel        being obtained by grafting a trialkoxysilane of formula        X—(CH₂)_(j′)—Si(OR)₃, wherein j′ is as defined above for formula        (IIa), and R is an alkyl group comprising 1 to 4 (typically 1        or 2) carbon atoms; and    -   the compounds (PAC^(f)) prepared in step (E2) are compounds        bearing —NH₂ functions as Fc functions, which fit the following        general formula (IIf-a2):

wherein:

-   -   a, b, c, d, p, Rc and R³ are as defined above for formula (IIa);        and    -   z′ is a saturated or unsaturated, linear or branched, divalent        hydrocarbon group, optionally totally or partly cyclized (for        example as an aryl) and optionally interrupted by one or more        heteroatoms, z′ may typically be a divalent alkylene group        containing 1 to 8 carbon atoms, for example 2, 3, 4 or 5 carbon        atoms. According to a specific embodiment, z′ may comprise a        carbonyl group, for example included in a urea function.

Preferably, according to this particular embodiment, in step (E2), thepreparation of the compounds (PAC^(f)) of formula (IIf-a2) applies thesuccession of following steps:

wherein Alk is an alkyl group comprising 1 to 4 carbon atoms.

According to a third specific embodiment with which extracting materialsbearing polyazacycloalkanes of formula (IIa) according to the secondalternative of the invention may be obtained, the method of theinvention is conducted as follows:

-   -   the solid support provided in step (E1) is a modified silica gel        which includes surface —Si—H functions, this modified silica gel        being obtained by grafting a trialkoxysilane of formula        H—Si(OR)₃, wherein R is an alkyl group comprising 1 to 4        (typically 1 or 2) carbon atoms; and    -   the compounds (PAC^(f)) prepared in step (E2) are compounds        bearing —CH═CH₂ functions as Fc functions, which fit the        following general formula (IIf-a3):

wherein:

-   -   a, b, c, d, p, Rc, and R³ are as defined above for formula (II);        and    -   -z′- is a saturated or unsaturated linear or branched divalent        hydrocarbon group optionally totally or partly cyclized and        optionally interrupted by one or more heteroatoms. z′ may        typically be a divalent alkylene group containing 1 to 8 carbon        atoms, for example 2, 3, 4 or 5 carbon atoms. According to a        specific embodiment, z′ may comprise a carbonyl group, for        example included in a urea function.

Preferably, according to this particular embodiment, in step (E2), thepreparation of the compounds (PAC^(f)) of formula (IIf-a3) applies thefunctionalization of the compound of the following formula:

with three aforementioned either identical or different Rc groups offormula —(CH₂)_(p)—(C═O)—NR³-z′-CH═CH₂. According to an embodiment whichmay be considered, 3 of the carbon atoms of the above tetracycliccompounds are first functionalized with three Rc groups (in one orseveral steps); and then the last nitrogen atom is functionalized with a—(CH₂)_(p)—(C═O)—NR³-z′-CH═CH₂ group. Alternatively, conversely, one ofthe nitrogen atoms of the tetracyclic compound may first befunctionalized with a —(CH₂)_(p)—(C═O)—NR³-z′-CH═CH₂ group, and then thethree other nitrogen atoms of the ring may be functionalized (in one orseveral steps) with three Rc groups.

According to another particular aspect, the object of the presentinvention is the use of the materials of the invention.

In a very general way, a material according to the invention proves tobe useful for scavenging metal ions, notably Pb²⁺ ions, but also Cd²⁺,Cu²⁺, Zn²⁺, Ni²⁺ cations, dissolved within a liquid medium, notablywithin an aqueous medium.

Within this scope, the materials of the invention may typically beapplied in methods for purifying liquid media (notably aqueous media)contaminated with metal cations, wherein the medium to be treated is putinto contact with an extracting material according to the invention.These methods, which may be applied according to a static or dynamicmode, are, according to a particular aspect, another object of thepresent invention.

A purification method applying an extracting material according to theinvention proves to be particularly interesting when the liquid medium(notably an aqueous medium) subject to the purification treatment isinitially contaminated with Pb²⁺ cations. As indicated above in thepresent description, by applying extracting materials within this scopeit is possible to easily attain very low lead contents in the treatedmedium, typically with a residual lead content of lower than 10 ppb,including when the purification method is conducted according to adynamic mode.

The purification method of the invention may advantageously be appliedto a treatment for purifying drinking water, for example by using theextracting material of the invention in a purifying cartridge placedupstream or downstream from a domestic drinking water distribution tap.

The purification method of the invention also finds interesting use fortreating industrial liquid effluents (notably aqueous effluents) orwaste waters.

Different aspects and advantages of the invention will furthermorebecome apparent in view of the illustrative examples discussedhereafter.

EXAMPLE 1 Preparation of the Material Si2323TAM

(Direct Condensation of a Macrocyclic Precursor Bearing a Silane Groupon Silica Gel)

In this example, a material of formula Si2323TAM as defined above in thepresent description was prepared according to the reaction schemehereafter:

More specifically, the procedure hereafter was applied:

Preparation of Compound 1.1 (TE3AM.HI)

This compound is obtained according to the operating procedure describedin Tetrahedron Lett., Vol. 40, pp. 381-382 (1999).

Preparation of Compound 1.2 (N-propyltriethoxysilyl-2-chloroacetamide)

Under a nitrogen atmosphere, 75 g (540 mmol) of potassium carbonate and21.5 mL (270 mmol) of chloroacetyl chloride are introduced in 200 mL oftetrahydrofurane. The mixture is cooled to 0° C.

To the cooled mixture are added 60 g (270 mmol) ofaminopropyltriethoxysilane, dissolved in 30 mL of tetrahydrofurane,within 15 minutes by means of an isobaric dropping funnel. Stirring ismaintained at room temperature of 18 h and then the reaction medium isfiltered on celite.

After removing in vacuo the solvent contained in the filtrate, 46.4 g ofthe compound 1.2 was obtained as a pale yellow oil (yield=57%) havingthe NMR characteristics hereafter:

¹H NMR (200 MHz, CDCl₃): 0.60 (t, 2H, ³J=7.4 Hz, CH ₂Si); 1.20 (t, 9H,³J=6.0 Hz, OCH₂CH ₃); 1.65 (p, 2H, ³J=7.4 Hz, CONHCH₂CH ₂); 3.25 (q, 2H,³J=7.4 Hz, CONHCH ₂); 3.80 (q, 6H, ³J=6.0 Hz, OCH ₂CH₃); 4.00 (s, 2H,ClCH ₂); 6.77+8.25 (m, 1H, CONH cis+trans).

¹³C NMR (50 MHz, CDCl₃): 7.9 (CH₂Si); 18.6 (OCH₂ CH₃); 23.0 (NHCH₂ CH₂);42.3 (NHCH₂); 42.9 (ClCH₂); 58.7 (OCH₂CH₃); 166.2 (CO).

Preparation of the Precursor 1.3

Under a nitrogen atmosphere, 39.5 g (79 mmol) of TE3AM.HI (compound1.1), 23.5 g (79 mmol) of the compound 1.2 and 27.4 g (200 mmol) ofpotassium carbonate are mixed with 800 mL of freshly distilledacetonitrile. The obtained suspension is refluxed with the solvent for44 h. The solvent is then evaporated. The obtained compound issolubilized in 1 L of chloroform and the solid residue is removed byfiltration.

After evaporation of the solvent, 31 g of compound 1.3 are isolated, asa yellow solid (yield=62%) having the NMR characteristics hereafter:

¹H NMR (500 MHz, DMSO-d⁶): 0.62 (m, 2H, CH ₂Si); 1.23 (t, 9H, ³J=6.0 Hz,OCH₂CH ₃); 1.59-1.68 (m, 4H, CH₂CH ₂CH₂); 1.96 (m, 2H, CH ₂CH₂Si); 2.64(m, 16H, CH ₂N); 3.06 (m, 8H, CH ₂CO); 3.24 (m, 2H, CONHCH ₂); 3.82 (q,6H, ³J=6.0 Hz, OCH ₂CH₃); 7.03 (m, 6H, CONH ₂).

¹³C NMR (125 MHz, DMSO-d⁶): 8.5 (CH₂Si); 19.1 (OCH₂ CH₃); 24.8 (CH₂CH₂CH₂); 25.9 (CH₂ CH₂CH₂); 55.4 (CH₂N); 58.6 (OCH₂CH₃); 171.5 (CO);175.8 (CO).

Mass spectroscopy (MALDI-TOF) m/z: 632.5 s [L]⁺.

Grafting of the Precursor 1.3 on Silica Gel

Grafting is carried out by putting 27.7 g (i.e. 44 mmol) of precursor1.3 in contact with 60 g of silica dehydrated by azeotropic distillation(Kieselgel 60 marketed by Merck; grain size fraction=0.25-0.40 mm;specific surface area=550 m² g⁻¹). The operation is performed under anitrogen atmosphere, in 1.25 L of freshly distilled toluene and heatedto 110° C., with mechanical stirring for 40 h.

The obtained modified gel is recovered at room temperature byfiltration, washed with ethanol, with ether and then dried in vacuo andsieved. 64.4 g of modified silica gel Si2323TAM are thereby obtainedhaving the characteristics hereafter:

RPE (copper-metal gel, T=100 K): g_(⊥)=2.10; g_(//)=2.23; a_(//)=147×10cm⁻¹.

IR (diffuse reflection, KBr, cm⁻¹): 3305 (v_(NH)); 2946 (v_(CH)); 2820(v_(CH)); 1673 (v_(CO)); 1092 (v_(SiO)); 795 (δ_(OSiO)).

Elementary analysis of the nitrogen element: 0.32 mmol g⁻¹ (% N: 3.57%).

X fluorescence of copper: 0.24 mmol g⁻¹.

Specific surface area (BET): 338 m² g⁻¹.

Total volume total of adsorbed nitrogen: 0.46 cm³ g⁻¹.

Average diameter of the pores (BJH): 40 {acute over (Å)} (distribution20-110 {acute over (Å)}).

EXAMPLE 2 Preparation of the Material Si2223TAMMe₂

(Direct Condensation of a Macrocyclic Precursor Bearing a Silane Groupon Silica Gel)

In this example, a material of formula Si2223TAMMe₂ as defined above inthe present description was prepared, according to the reaction schemehereafter:

More specifically, the procedure hereafter was applied:

Preparation of Compound 2.1

The precursor 2.1 is obtained starting with tetraamine1,4,7,10-tetraazacyclotridec-5-yl-methanol, the preparation of which wasdescribed in the international application WO 03/029228.

A solution containing 7.70 g (35.60 mmol) of tetraamine1,4,7,10-tetraazacyclotridec-5-yl-methanol in 500 mL of acetonitrile and39.36 g (284.80 mmol) of potassium carbonate is refluxed before addingin a single portion 21.66 g (176.20 mmol) of2-chloro-N,N-dimethylacetamide. The mixture is then left under stirringand refluxed for 5 days.

After filtration on celite and evaporation of the solvent in vacuo, aresidual red oil is obtained which is purified by chromatography on analumina column (eluent: dichloromethane/methanol 98:2 v/v).

5.5 g of the compound 2.1 are then obtained, as a yellow oil (yield=28%)having the characteristics hereafter:

¹H NMR (500 MHz, CDCl₃): 1.56 (m, 2H); 2.39 (m, 1H); 2.45-3.10 (m, 14H);2.85 (s, 3H); 2.87 (s, 9H); 2.93 (s, 3H); 2.97 (s, 3H); 3.01 (s, 3H);3.02 (s, 3H); 3.15-3.6 (m, 11 H).

¹³C NMR (125 MHz, CDCl₃): 24.2 (CH₂ CH₂CH₂); 35.8 (3C, NCH₃); 36.1(NCH₃); 36.8 (NCH₃); 37.1 (NCH₃); 37.4 (2C, NCH₃); 50.8 (2C, NCH₂); 50.9(NCH₂); 51.5 (NCH₂); 52.1 (2C, NCH₂); 54.7 (NCH₂); 54.8 (NCH₂); 57.4(2C, CH₂CO); 58.0 (CH₂CO); 60.2 (CH₂CO); 62.5 (CH₂OH); 170.9 (CO); 171.0(CO); 171.1 (CO); 172.8 (CO).

Mass spectroscopy (MALDI-TOF) m/z: 557.7 [L]⁺.

Preparation of Compound 2.3

To a solution of 7.40 g (13.29 mmol) of the compound 2.1 dissolved in100 mL of dichloromethane in the presence of 3 mL of triethylamine, 3.90g (i.e. 13.29 mmol) of the compound 2.2(3-isocyanatopropyltriethoxysilane marketed by Aldrich—purity >95%) areadded.

The mixture is stirred at room temperature for 12 h. Analysis byinfrared spectroscopy gives the possibility of tracking the progressionof the reaction and of noticing the disappearance of the characteristicband of the N═C═O function at 2272 cm⁻¹.

At the end of the reaction, the solvent is evaporated in vacuo therebyallowing isolation of the compound 2.3 as an orange oil, which is usedwithout any further purification in the step below.

Grafting of the Precursor 2.3 on Silica Gel

Grafting is carried out by putting the whole of the compound 2.3 (orangeoil) obtained in the previous step in contact with 31.00 g of silica,dehydrated by azeotropic distillation (Kieselgel 60—Merck; grain sizefraction=0.25-0.40 mm; specific surface area=550 m² g⁻¹). The reactionis conducted in 250 mL of distilled xylene which are refluxed andmechanically stirred under an argon atmosphere for 72 h.

The modified gel is recovered at room temperature by filtration, washedwith water, with ethanol and with chloroform, and then dried in vacuoand sieved.

34.90 g of modified silica gel Si2223CTAMMe₂ are thereby obtained,having the characteristics hereafter:

Elementary analysis of the nitrogen element: 0.22 mmol g⁻¹ (% N: 2.46%).

X fluorescence of copper: 0.15 mmol g⁻¹.

EXAMPLE 3 Preparation of the Material Si2323UENTAM

(Direct Condensation of a Macrocyclic Precursor Bearing a Silane Groupon Silica Gel)

In this example, a material of formula Si2323UENTAM as defined above inthe present description was prepared according to the reaction schemehereafter:

More specifically, the procedure below was applied:

Preparation of Compound 3.1

This compound is prepared according to the procedure described for thecompound 4.2 of Example 4 hereafter.

Preparation of the Precursor 3.3

To a solution of 2.96 g (6.3 mmol) of compound 3.1 dissolved in 40 mL offreshly distilled absolute ethanol, 1.64 mL (6.3 mmol) of compound 3.2(3-isocyanatopropyltriethoxysilane marketed by Aldrich, of purity >95%)are added. The mixture is heated and refluxed with ethanol for 24 h.Analysis by infrared spectroscopy gives the possibility of following theprogression of the reaction and of noticing the disappearance of thecharacteristic band of the N═C═O function at 2272 cm⁻¹. The solvent isevaporated in vacuo and the compound 3.3 obtained is used as such in thefollowing step.

Grafting of the Precursor 3.3 on Silica Gel

Grafting is carried out by putting 3.5 g (4.87 mmol) of precursor 3.3 incontact with 4.87 g of silica dehydrated by azeotropic distillation(Kieselgel 60—Merck; grain size fraction=0.25-0.40 mm; specific surfacearea=550 m² g⁻¹). The reaction is conducted in 50 mL of distilledtoluene refluxed under mechanical stirring, under an argon atmospherefor 24 h.

The modified gel is recovered at room temperature by filtration, washedwith toluene, with ethyl ether, and then dried in vacuo.

7.83 g of modified silica gel Si2323UENTAM are thereby obtained havingthe following characteristics:

Elementary analysis of the nitrogen element: 0.49 mmol g⁻¹ (% N: 6.86%).

EXAMPLE 4 Preparation of the Material Si2323ENTAM

(Grafting Involving Nucleophilic Substitution)

In the present Example 4, as well as in both Examples 5 and 6 whichfollow, a material according to the invention is prepared by reacting anaminated precursor with silica gel grafted beforehand with compoundsbearing —Cl functions (introduced by reaction of the silica withchloropropyltriethoxysilane compounds). This modified silica gel,so-called SiCl, which has the following structure:

is prepared according to the procedure hereafter:

60 g of silica dehydrated by azeotropic distillation (Kieselgel60—Merck; grain size fraction=0.25-0.40 mm; specific surface area=550 m²g⁻¹) and 6 g (25 mmol) of chloropropyltriethoxysilane are mixed in 100mL of toluene under a nitrogen atmosphere. The obtained mixture ismaintained refluxed with the solvent for 24 h. After filtration, washingwith dichloromethane and drying, the material is sieved. The sought SiClgel is thereby obtained which has the following properties:

IR (diffuse reflection, KBr, cm⁻¹): 3624 (v_(OH)); 2980 (v_(CH)); 2961(v_(CH)); 2936 (v_(CH)); 2898 (v_(CH)); 1630 (δ_(OH)); 1446 (δ_(CH2));1395 (δ_(CH2)); 1096 (v_(SiO)); 793 (δ_(OSiO)).

Elementary analysis of the chlorine element: 0.3 mmol g⁻¹ (% Cl=1.02%).

Specific surface area (BET): 464 m² g⁻¹.

Total volume of adsorbed nitrogen: 0.61 cm³ g⁻¹.

Average diameter of the pores (BJH): 55 {acute over (Å)} (distribution20-120 {acute over (Å)}).

Specifically, in the present example 4, a material of formulaSi2323ENTAM as defined above in the present description was preparedaccording to the reaction scheme hereafter:

More specifically, the procedure hereafter was applied:

Preparation of Compound 4.1

The monoester 4.1 is prepared by maintaining for 48 h reflux of 1 L ofacetonitrile containing 15 g (30 mmol) of triacetamide 1.1, 5 g (30mmol) of ethyl bromoacetate and 10.5 g (75 mmol) of potassium carbonate.

After filtration and evaporation of the solvent, 13.5 g of the desiredcompound 4.1 are isolated as a white solid (yield=98%). The compound hasthe following characteristics:

¹H NMR (300 MHz, CDCl₃): 1.14 (t, 3H, ³J=6.0 Hz, OCH₂CH ₃); 1.55 (m, 4H,CH₂CH ₂CH₂); 2.50 (s, 16H, CH ₂N); 2.93 (s, 6H, CH ₂CONH₂); 3.14 (s, 2H,CH ₂COOEt); 4.02 (q, 2H, ³J=6.0 Hz, OCH ₂CH₃); 6.13 (s, 1H, CONH); 6.68(s, 2H, CONH); 7.03 (s, 1H, CONH); 7.22 (s, 1H, CONH); 7.89 (s, 1H,CONH).

¹³C NMR (75 MHz, CDCl₃): 14.7 (OCH₂ CH₃); 26.0 (CH₂ CH₂CH₂); 26.3 (CH₂CH₂CH₂); 52.4-54.3 (CH₂N); 56.1 (CH₂N); 59.1 (CH₂CONH₂); 59.4(CH₂COOEt); 61.4 (OCH₂CH₃); 172.4 (COOEt); 176.3 (CONH₂); 176.5 (CONH₂);176.95 (CONH₂).

Mass spectroscopy (MALDI-TOF) m/z: 458.3 [L+H]⁺.

Preparation of the Precursor 4.2 Macrocyclic Precursor Bearing a PrimaryAmine

To 13 g (32.7 mmol) of the compound 4.1 dissolved in 700 mL of absoluteethanol, are added 200 equivalents of ethylenediamine (380 mL; 6.5 mol).The reaction mixture is maintained refluxed for 24 h under a nitrogenatmosphere. The solvent and the excess ethylenediamine are evaporatedbefore drying the residue in vacuo (T=50° C., P=4 torrs).

The sought compound 4.2 is isolated as 13.7 g of a white powder(yield=89%), having the following characteristics:

¹H NMR (300 MHz, D₂O): 1.61 (m, 4H, CH₂CH ₂CH₂); 2.49-2.61 (m, 18H, CH₂N); 3.03 (m, 8H, CH₂CO); 3.15 (t, 2H, ³J=6.4 Hz, CONHCH ₂).

¹³C NMR (75 MHz, D₂O): 23.2 (CH₂ CH₂CH₂); 40.4-52.5 (CH₂N); 57.8-58.7(CH₂CO); 174.7 (CO); 177.0 (CO); 177.7 (CO).

Grafting of the Precursor 4.2 on SiCl Gel Nucleophilic Substitution

Grafting is carried out by putting 15 g (32 mmol) of compound 4.2 incontact with 65 g of modified silica SiCl and 10 g (72 mmol) ofpotassium carbonate dissolved in 600 mL of acetonitrile. The medium ismaintained refluxed under mechanical stirring for 48 h. After returningto room temperature, after filtration, drying and sieving, 70 g of amaterial Si2323ENTAM are obtained having the characteristics hereafter:

RPE (copper-metal gel, T=100 K): g_(⊥)=2.07; g_(//)=2.23; a_(//)=156×10⁴cm⁻¹.

IR (diffuse reflection, KBr, cm⁻¹): 3733 (v_(OH)); 3294 (v_(OH)); 2943(v_(CH)); 2889 (v_(CH)); 1669 (v_(CO)); 1538 (δ_(CNH)); 1456 (v_(CN));1087 (v_(SiO)); 797 (δ_(OSiO)).

Elementary analysis of the nitrogen element: 0.18 mmol g⁻¹ (% N: 2.22%).

X fluorescence of copper: 0.18 mmol g⁻¹.

Specific surface area (BET): 368 m² g⁻¹.

Total volume of adsorbed nitrogen: 0.57 cm³ g⁻¹.

Average diameter of the pores (BJH): 60 {acute over (Å)} (distribution20-120 {acute over (Å)}).

EXAMPLE 5 Preparation of the Material Si2323ENTAMMe₂

(Grafting Involving Nucleophilic Substitution)

In this example, a material of formula Si2323ENTAMMe₂ as defined abovein the present description was prepared according to the reaction schemebelow:

More specifically, the procedure hereafter was applied:

Preparation of Compound 5.1

The precursor 5.1 is prepared in two steps from cyclam.

In a first phase, ethyl (1,4,8,11-tetraazacyclotetradec-1-yl)ethanoateis obtained by slowly adding 6.68 g (40.0 mmol) of ethyl bromoacetateonto a solution of 40 g (200.0 mmol) of cyclam and 16 g (116 mmol) ofpotassium carbonate in 1 L of chloroform. The reaction mixture ismaintained under stirring at room temperature for 48 h. After filtrationon celite and evaporation of the solvent, the residue is taken up inpetroleum ether. The excess cyclam is filtered off, the filtrate isconcentrated and ethyl (1,4,8,11-tetraazacyclotetradec-1-yl)ethanoate(so-called compound 5.0) is thereby obtained, as 11.21 g of a slightlyyellow oil (yield=98%) which is used without any purification.

The three secondary amines of the obtained monoester 5.0 are thenfunctionalized with 2-chloro-N,N-dimethylacetamide (this chlorinatedreagent is preferred to its brominated analog which leads to theformation of a significant amount of quaternized products). To do this,the 11.21 g (i.e. 39.2 mmol) of the compound 5.0 obtained previously aredissolved in 100 mL of acetonitrile and this solution is added dropwiseinto a solution of 14.28 g (117 mmol) of 2-chloro-N,N-dimethylacetamideand 35 g (252 mmol) of potassium carbonate in 900 mL of acetonitrilebrought to 30° C. The reaction medium is maintained at 45° C. withstirring for 48 h.

After filtration on celite and evaporation of solvent, the compound 5.1is obtained as 20.2 g of a slightly yellow solid (yield=95%), having thefollowing characteristics:

¹H NMR (500 MHz, CDCl₃): 1.21 (t, 3H, OCH₂CH ₃); 1.57 (m, 4H, CH₂CH₂CH₂); 2.50-2.63 (m, 16H, CH ₂N); 2.88 (s, 9H, NCH ₃); 3.04 (s, 3H, NCH₃); 3.07 (s, 3H, NCH ₃); 3.10 (s, 3H, NCH ₃); 3.23-3.27 (m, 8H, CH₂CONH₂ and CH ₂CO₂Et); 4.09 (q, 2H, OCH ₂CH₃).

¹³C NMR (125 MHz, CDCl₃): 14.9 (OCH₂ CH₃); 25.2 (CH₂ CH₂CH₂); 25.4 (CH₂CH₂CH₂); 36.1-38.1 (NCH ₃); 51.1-52.5 (CH₂N); 56.0 (CH₂CO₂Et); 57.8(CH₂CONH₂); 58.1 (CH₂CONH₂); 58.4 (CH₂CONH₂); 60.8 (OCH₂CH₃); 171.3(CO₂Et); 171.5 (CONMe₂); 171.6 (CONMe₂); 172.0 (CONMe₂).

Mass spectroscopy (MALDI-TOF) m/z: 541.8 [L]⁺.

Elementary analysis: C, 57.93; H, 9.70; N, 17.93. (As an indication, thedata calculated for C₂₆H₅₁N₇O₅ (M=541.40) are the following: C, 57.65;H, 9.49; N, 18.10).

Preparation of the Precursor 5.2 Macrocyclic Precursor Bearing a PrimaryAmine

A solution of 12.09 g (22.33 mmol) of compound 5.1 and 240 mL (43 mol)of ethylenediamine in 900 mL of ethanol is refluxed with heating for 48h.

After evaporation of the solvent and of the excess ethylenediamine, thecompound 5.2 is obtained as 11.50 g of a slightly yellow solid (yield:93%), having the following characteristics:

¹H NMR (500 MHz, CDCl₃): 1.39 (m, 4H, CH₂CH ₂CH₂); 2.27-2.52 (m, 20H, CH₂N); 2.59 (s, 9H, NCH ₃); 2.71 (s, 3H, NCH ₃); 2.76 (s, 3H, NCH ₃); 2.82(s, 3H, NCH ₃); 2.96-3.01 (m, 8H, CH₂CO); 7.66 (t, 1H, CONHCH₂).

¹³C NMR (125 MHz, CDCl₃): 24.5 (CH₂ CH₂CH₂); 25.0 (CH₂ CH₂CH₂);35.3-37.1 (NCH ₃); 41.7 (CH₂N); 41.9 (CH₂N); 50.6-52.0 (CH₂N); 56.0(CH₂CO); 56.7 (CH₂CO); 57.4 (CH₂CO); 58.4 (CH₂CO); 170.1 (CO); 170.4(CO); 170.6 (CO); 172.2 (CO).

Mass spectroscopy (MALDI-TOF) m/z: 556.2 [L+H]⁺.

Grafting of the Precursor 5.2 on the SiCl Gel Nucleophilic Substitution

Grafting is carried out by putting 10.27 g (18.5 mmol) of compound 5.2in contact with 60 g of modified silica SiCl and 6.9 g (50 mmol) ofpotassium carbonate dissolved in 400 mL of acetonitrile. The medium ismaintained under reflux with mechanical stirring for 48 h. Afterreturning to room temperature, filtration, drying and sieving, 65 g ofmaterial Si2323ENTAMMe₂ are obtained having the characteristicshereafter:

RPE (copper-metal gel, T=100 K): g_(⊥)=2.07; g_(//)=2.23; a_(//)=156×10⁴cm⁻¹.

Elementary analysis of the nitrogen element: 0.18 mmol g⁻¹ (% N: 2.02%).

X fluorescence of copper: 0.10 mmol g⁻¹.

Specific surface area (BET): 356 m² g⁻¹.

Total volume of adsorbed nitrogen: 0.74 cm³ g⁻¹.

Average diameter of the pores (BJH): 83 {acute over (Å)} (distribution30-160 {acute over (Å)}).

EXAMPLE 6 Preparation of the Material Si2323CTAMMe₂

(Grafting Involving a Nucleophilic Substitution)

In this example, a material of formula Si2323CTAMMe₂ as defined earlierin the present description was prepared according to the reaction schemehereafter:

Preparation of Compound 6.2

The synthesis of the precursor 6.2 initially proceeds with the methylester 6.1 (methyl 1,4,8,11-tetraazacyclotetradecane-6-carboxylate), thesynthesis of which was described in the application WO 03/029228. To20.53 g (148.0 mmol) of potassium carbonate and 5.00 g (12.38 mmol) ofthe compound 6.1.4HCl dissolved in 500 mL of refluxed acetonitrile, areadded in a single portion, 6.02 g (12.38 mmol) of2-chloro-N,N-dimethylacetamide, and then the mixture is refluxed for 5days with stirring. After filtration on celite and evaporation of thesolvent, a yellow oil is obtained, which is purified by chromatographyon an alumina column (eluent: dichloromethane and thendichloromethane/methanol 2:98 v/v). The head fraction corresponds to thecompound 6.2 which is isolated as 3.70 g of a colorless oil afterevaporating the solvent in vacuo (yield=62%), the obtained compoundhaving the following characteristics:

¹H NMR (500 MHz, CDCl₃): 1.61 (m, 2H); 2.52-3.05 (m, 17H); 2.83 (s, 6H);2.87 (s, 6H); 2.95 (s, 6H); 3.03 (s, 6H); 3.18 (d, 2H, ³J=14.0 Hz); 3.29(d, 2H, ³J=14.0 Hz); 3.31 (s, 4H); 3.60 (s, 3H).

¹³C NMR (125 MHz, CDCl₃): 25.2 (CH₂ CH₂CH₂); 36.0 (NCH₃); 36.1 (NCH₃);37.5 (NCH₃); 37.6 (NCH₃); 45.2 (CHCO₂Me); 51.4 (CH₂N); 51.6 (CH₂N); 52.2(CH₂N); 52.3 (CO₂ CH₃); 55.9 (CH₂N); 58.3 (CH₂CO); 58.4 (CH₂CO); 171.1(CONMe₂); 171.2 (CONMe₂); 176.0 (CO₂Me).

Mass spectroscopy (MALDITOF) m/z: 599.2 [M]⁺.

Preparation of the Precursor 6.3 Macrocyclic Precursor Bearing a PrimaryAmine

A solution containing 28.0 g (46.76 mmol) of the monoester 6.2 preparedpreviously and 562.0 g (9.36 mol) of ethylenediamine dissolved in 1 L ofethanol is heated to 60° C. for 48 h. After evaporation of the solventand of the excess ethylenediamine, the compound 6.3 is quantitativelyisolated and is used without any subsequent purification in the nextstep.

Grafting of the Precursor 6.3 on SiCl Gel Nucleophilic Substitution

A mixture consisting of 19.00 g (30.0 mmol) of the compound 6.3, 12.40 g(90.0 mmol) of potassium carbonate and 60.00 g of modified silica gelSiCl in 400 mL of acetonitrile are refluxed for 72 h with heating. Afterfiltration and washing with water, ethanol and chloroform, and thendrying, 64.1 g of a material Si2323CTAMMe₂ are obtained, having thefollowing characteristics:

Elementary analysis of the nitrogen element: 0.10 mmol g⁻¹ (% N: 1.12%).

X fluorescence of copper: 0.11 mmol g⁻¹.

EXAMPLE 7 Preparation of the Material Si2323TAM

(Grafting Involving Catalytic Hydrosilylation)

In this Example 7 and in Examples 8 and 9 which follow, a materialaccording to the invention was prepared by reacting a precursor bearinga vinyl end group with silica gel treated with triethoxysilane. Thissilica gel which will be designated hereafter by “SiH”, was prepared byfollowing the procedure described by Chu et al. in Anal. Chem., Vol. 65,pp. 808-816 (1993). More specifically, 5 g of silica dehydrated byazeotropic distillation (Kieselgel 60-Merck; grain sizefraction=0.25-0.40 mm; specific surface area=550 m² g⁻¹) are suspendedin 100 mL of dioxane also containing 1.6 mL of a 35% hydrochloric acidsolution. The mixture is mechanically stirred and heated to 75° C.before introducing over a period of 15 min, 3.7 g (22.5 mmol) oftriethoxysilane diluted in 45 mL of dioxane. Heating is maintained for 1h before filtering the mixture and drying the gel. The modified gel SiHobtained has the following characteristics:

IR (diffuse reflection, KBr, cm⁻¹): 2250 (v_(SiH)).

In the present Example 7, a precursor 7.2 of the following formula wasgrafted:

on the SiH gel.

This compound 7.2 was obtained starting with a precursor 7.1 accordingto the following procedure:

Preparation of the Precursor 7.1

Under a nitrogen atmosphere, 10.6 mL (133 mmol) of chloroacetyl chlorideand 30 g (266 mmol) of potassium carbonate are mixed in 500 mL ofdichloromethane. The mixture is cooled to 0° C.

20 mL (133 mmol) of allylamine dissolved in 50 mL of dichloromethane arethen added. The addition is carried out over a period of 15 minutes bymeans of an isobaric dropping funnel. Stirring is maintained at roomtemperature for 18 h and the mixture is then filtered on celite. Byevaporating the solvent, the compound 7.1 is obtained as 16.3 g of apale yellow oil (yield=92%), having the following characteristics:

¹H NMR (200 MHz, CDCl₃): 3.87 (t, 2H, ³J=5.7 Hz, CONHCH ₂); 4.03 (s, 2H,CH ₂Cl); 5.09 (d, 1H, ³J_(cis)=12 Hz, CH═CH ₂); 5.13 (d, 1H,³J_(trans)=17 Hz, CH═CH ₂); 5.80 (ddt, 1H, ³J=5.7 Hz, ³J_(cis)=12 Hz,³J_(trans)=17 Hz, CH═CH₂); 6.87 (broad s, 1H, CONH).

¹³C NMR (50 MHz, CDCl₃): 42.4 (NHCH₂); 42.8 (ClCH₂); 117.2 (CH═CH₂);133.3 (CH═CH₂); 166.6 (CO).

Preparation of Compound 7.2

The vinyl precursor 7.2 is synthesized from the compound 1.1 prepared inExample 1 (i.e. the trisubstituted compound TE3AM.HI). Morespecifically, 10 g (20 mmol) of the compound 1.1 are dissolved in 100 mLof water and the solution is set to boil. 2.67 g (20 mmol) of thecompound 7.1 are then added in a single portion, to the boiling medium,while maintaining the pH of the medium above 12 by addingbenzyltrimethylammonium hydroxide (in a 40% (by mass) aqueous solution).Heating is maintained for 2 h under these conditions, and then thesolvent is removed by evaporation in vacuo, whereby an oily yellowresidue is obtained. Addition of 100 mL of acetone and 20 mL of ethanolto this residue leads to precipitation of a while solid which isisolated, washed with 100 mL of acetone and 100 mL of ether and thendried in vacuo, whereby 5.5 g of the sought compound 7.2 are obtained(yield=59%), having the characteristics hereafter:

¹H NMR (200 MHz, D₂O+DCl, pD<1): 2.10 (m, 4H, CH₂CH ₂CH₂); 3.38 (m, 8H,CH ₂N); 3.64-3.71 (m, 10H, CH ₂N+CONHCH ₂); 4.02 (broad s, 8H, CH ₂CO);5.00 (m, 1H, CH═CH ₂); 5.03 (m, 1H, CH═CH ₂); 5.64 (m, 1 H, CH═CH₂).

¹³C NMR (50 MHz, D₂O+DCl, pD<1): 18.58 (CH₂ CH₂CH₂); 42.34 (CONHCH₂);46.38 (CH₂N); 50.17 (CH₂N); 56.80 (CH₂CONH₂); 57.08 (CH₂CONH); 116.75(CH═CH₂); 133.38 (CH═CH₂); 164.92 (CONH); 167.35 (CONH₂).

IR (KBr, cm⁻¹): 3392 (v_(NH)); 2925 (v_(CH)); 2879 (v_(CH)); 2827(v_(CH)); 1679 (v_(CO)); 1597 (v_(C═C)); 1384 (v_(CN)); 1159 (v_(CN));1060 (δ_(CH allyl)); 623 (ω_(NH)).

Mass spectroscopy (MALDI-TOF) m/z: 468.9 [L+H]⁺; 490.7 [L+Na]⁺; 506.2[L+K]⁺.

Grafting of the Precursor 7.2 on SiH Silica Gel

1 g of SiH gel and 1 mmol of compound 7.2 are mixed with mechanicalstirring in 50 mL of ethanol containing 2% molar of hydrosilylationcatalyst (40% Pt hexachloroplatinic acid hydrate). The reaction mediumis brought to 80° C. for 48 h. The material is then recovered byfiltration, washed with ethanol, with water and then with acetone,before being dried in vacuo. It has the following characteristics:

IR (diffuse reflection, KBr, cm⁻¹): 3300 (v_(NH)); 2977 (v_(CH)); 2820(v_(CH)); 1665 (v_(CO)); 1092 (v_(SiO)); 792 (δ_(OSiO)).

Elementary analysis of the nitrogen element: 0.11 mmol g⁻¹ (% N: 1.28%).

Comments:

The grafting mode described here is purely an indication and may bemodified to quite an extent. For example a solvent other than ethanol(2-propanol or acetonitrile notably) may be used and/or anotherhydrosilylation catalyst such as for example a Wilkinson catalyst may beused.

Moreover, in situ grafting of the precursors on a non-modified silicagel may alternatively be used, by reversing the addition order of thetriethoxysilane. In this case, the vinyl or styrene precursor is firstsilylated via a catalytic route with an agent such as (40% Pt)hexachloroplatinic acid hydrate or the Wilkinson reagent, and then theobtained reagent is condensed in situ on the silanol functions of anon-modified dehydrated silica gel.

These comments are valid for the graftings described in Examples 8 and 9which follow.

EXAMPLE 8 Preparation of the Material Si2323TAMMe₂

(Grafting Involving Catalytic Hydrosilylation)

In this example, a precursor 8.2 of the following formula was grafted:

on the aforementioned SiH gel.

This compound 8.2 was obtained starting with a precursor 8.1, itselfobtained from the precursor 7.1 of the previous Example 7, according tothe procedure detailed hereafter:

Preparation of the Precursor 8.1 from the Precursor 7.1

5 g (25 mmol) of cyclam (1,4,8,11-tetraazacyclotetradecane), 830 mg(6.25 mmol) of the compound 7.1 prepared in Example 7, and 2.6 g (18.75mmol) of potassium carbonate are mixed in 100 mL of tetrahydrofurane,and then the mixture is refluxed for 16 h. After evaporation of thesolvent in in vacuo, a residue is obtained which is extracted with 3×100mL of pentane. The obtained organic phase is filtered and the solvent isevaporated, whereby the product 8.1 is obtained as 1.65 g of a white oil(yield=88%), having the characteristics hereafter:

¹H NMR (300 MHz, CDCl₃): 1.65 (m, 4H, CH₂CH ₂CH₂); 2.50-2.70 (m, 16 H,CH ₂N); 3.02 (s, 2H, CH ₂CO); 3.84 (m, 2H, CONHCH ₂); 5.04 (d, 1H,³J_(cis)=10.0 Hz, CH═CH ₂); 5.13 (d, 1H, ³J_(trans)=17.0 Hz, CH═CH ₂);5.80 (ddt, 1H, ³J=5.5 Hz, ³J_(cis)=10.0 Hz, ³J_(trans)=17.0 Hz; CH═CH₂);8.63 (broad s, 1H, CONH).

¹³C NMR (75 MHz, CDCl₃): 26.88 (CH₂ CH₂CH₂); 29.08 (CH₂ CH₂CH₂); 41.93(CONHCH₂); 47.66 (CH₂N); 48.19 (CH₂N); 48.57 (CH₂N); 49.11 (CH₂N); 49.32(CH₂N); 50.87 (CH₂N); 54.13 (CH₂N); 56.72 (CH₂N); 58.53 (CH₂N); 116.13(CH═CH₂); 135.56 (CH═CH₂); 171.98 (CO).

Mass spectroscopy (MALDI-TOF) m/z: 298.1 [L+H]⁺.

Preparation of Compound 8.2

The compound 8.2 was obtained by trifunctionalization of the macrocyclicprecursor 8.1. To do this, 2.7 g (9.09 mmol) of compound 8.1 was reactedwith 3.3 g (27.3 mmol) of 2-chloro-N,N-dimethylacetamide, in thepresence of 9 g (75 mmol) of potassium carbonate, in 350 mL of refluxedacetonitrile. After 48 h of reaction, the solvent is evaporated in vacuoand the residue is extracted with 200 mL of chloroform. After removingthe solvent, an oil is obtained which is diluted in 200 mL of acetone.By evaporating the solvent, 3.0 g of the sought compound 8.2 (yield=60%)are obtained, having the characteristics hereafter:

¹H NMR (500 MHz, CDCl₃): 1.79 (m, 4H, CH₂CH ₂CH₂); 2.74-2.82 (m, 16H, CH₂N); 3.07-3.32 (m, 18H, NCH₃); 3.45 (m, 8H, CH ₂CO); 4.04 (m, 2H, CONHCH₂); 5.27 (d, 1H, ³J_(cis)=10.0 Hz, CH═CH ₂); 5.33 (d, 1H,³J_(trans)=16.2 Hz, CH═CH ₂); 6.00 (m, 1H, CH═CH₂); 8.19 (s, 1H, CONH).

¹³C NMR (125 MHz, CDCl₃): 25.34 (CH₂ CH₂CH₂); 25.91 (CH₂ CH₂CH₂); 35.67(CONMe); 35.82 (CONMe); 36.03 (CONMe); 37.02 (CONMe); 37.32 (CONMe);37.50 (CONMe); 42.03 (CONHCH₂); 50.91 (CH₂N); 51.37 (CH₂N); 51.87(CH₂N); 52.08 (CH₂N); 52.50 (CH₂N); 52.63 (CH₂N); 53.10 (CH₂N); 53.40(CH₂N); 55.80 (CH₂N); 57.19 (CH₂N); 57.90 (CH₂N); 116.60 (CH═CH₂);135.08 (CH═CH₂); 170.52 (CONMe₂); 170.85 (CONMe₂); 171.10 (CONMe₂);172.27 (CONH).

IR (KBr, cm⁻¹): 3434 (v_(NH)); 2941 (v_(CH)); 2797 (v_(CH)); 1643(v_(CO)); 1412 (v_(CN)); 1119 (v_(CN)).

Mass spectroscopy (MALDI-TOF) m/z: 553.3 [L+H]⁺; 575.0 [L+Na]⁺.

Elementary analysis: C, 57.93; H, 9.62; N, 19.67. (for information, thevalues calculated for C₂₇H₅₂N₈O₄ (M=552.75) are C, 58.67; H, 9.48; N,20.27).

Grafting of the Precursor 8.2 on Silica Gel SiH

1 g of SiH gel and 1 mmol of compound 8.2 are mixed with mechanicalstirring in 50 mL of ethanol containing 2% molar of a hydrosilylationcatalyst (40% Pt hexachloroplatinic acid hydrate). The reaction mediumis brought to 80° C. for 48 h. The material is then recovered byfiltration, washed with ethanol, with water and then with acetone,before being dried in vacuo. The obtained material Si2323TAMMe₂ has thefollowing characteristics:

Elementary analysis of the nitrogen element: 0.08 mmol g⁻¹ (% N: 0.89%).

EXAMPLE 9 Preparation of the Material Si2323TAMvinyl

(Grafting Involving Catalytic Hydrosilylation)

In this example, a precursor 9.2 of the formula was grafted:

on the aforementioned SiH gel.

The compound 9.2 was obtained starting with the precursor 7.1 of theprevious Example 7, according to the procedure hereafter:

Preparation of the Precursor 9.2 from the Precursor 7.1

To a solution of 5 g (25 mmol) of cyclam(1,4,8,11-tetraazacyclotetradecane) dissolved in 50 mL of water heatedto 80° C. and kept under stirring, 16.6 g (125 mmol) of the compound 7.1of Example 7 are added all at a time. The reaction medium is left at 80°C. for 15 minutes while maintaining the pH of the medium at a valueabove 12 by adding KOH tablets. The medium is then left under stirringwithout heating for 30 minutes more. The formed compound 9.2 isextracted from the reaction medium by extraction with 3×50 mL ofchloroform. The fractions are collected, the organic phase is dried, thesolvent is evaporated in vacuo, and then the obtained yellow residue isrecrystallized from acetone, whereby the compound 9.2 is obtained as4.07 g of fine transparent needles (yield=28%), having thecharacteristics hereafter:

¹H NMR (500 MHz, CDCl₃): 1.64 (p, 4H, ³J=6.7 Hz, CH₂CH ₂CH₂); 2.52 (t,8H, ³J=6.7 Hz, CH₂CH₂CH ₂N); 2.58 (s, 8H, CH₂CH ₂N); 3.01 (s, 8H, CH₂CO); 3.83 (t, 8H, ³J=6.0 Hz, CONHCH ₂); 5.11 (d, 4H, ³J_(cis)=10.0 Hz,CH═CH₂); 5.17 (d, 4H, ³J_(trans)=17.0 Hz, CH═CH ₂); 5.80 (ddt, 4H,³J=6.0 Hz, ³J_(cis)=10.0 Hz, ³J_(trans)=17.0 Hz, CH═CH₂); 7.10 (t, 4H,³J=6.0 Hz, CONH).

¹³C NMR (125 MHz, CDCl₃): 25.46 (CH₂ CH₂CH₂); 42.05 (CONHCH₂); 51.21(CH₂N); 52.63 (CH₂N); 58.61 (CH₂CO); 117.59 (CH═CH ₂); 134.48 (CH═CH₂);170.87 (CONH).

IR (KBr, cm⁻¹): 3283 (v_(NH)); 3062 (v_(CH allyl)); 2980 (v_(CH)); 2951(v_(CH)); 2925 (v_(CH)); 2830 (v_(CH)); 1649 (v_(CO)); 1551 (v_(C═C));1260 (v_(CN)); 996 (δ_(CH allyl)); 929 (δ_(CH allyl)); 709 (ω_(NH)).

Mass spectroscopy (MALDI-TOF) m/z: 589.3 [L+H]⁺; 610.8 [L+Na]⁺; 626.7[L+K]⁺.

Grafting of the Precursor 9.2 on Silica Gel SiH

1 g of SiH gel and 1 mmol of compound 9.2 are mixed with mechanicalstirring in 50 mL of ethanol containing 2% molar of a hydrosilylationcatalyst (40%-Pt hexachloroplatinic acid hydrate). The reaction mediumis brought to 80° C. for 48 h. The material is then recovered byfiltration, washed with ethanol, with water and then with acetone beforebeing dried in vacuo. The obtained material Si2323TAMvinyl has thefollowing characteristics:

IR (diffuse reflection, KBr, cm⁻¹): 3733 (v_(SiOH)); 3700-3200(v_(OH)+v_(NH)); 3080 (v_(CH allyl)); 2982 (v_(CH)); 2938 (v_(CH)); 2891(v_(CH)); 1656 (v_(CO)); 1534 (δ_(CNH)); 1090 (v_(SiO)); 803 (δ_(OSiO)).

Elementary analysis of the nitrogen element: 0.21 mmol g⁻¹ (% N: 2.31%).

EXAMPLE 10 Example of Application of the Material Si2323TAM

Purification of Water of the Type Lead-Contaminated Drinking Water

(Chromatography Column)

In this example, the extracting properties of the material Si2323TAM asprepared in Example 1 are demonstrated, towards different cationspresent in drinking water artificially contaminated with Pb²⁺ cations.

The contaminated water used for the test is drinking water having thefollowing physico-chemical characteristics:

Temperature: 17.6° C. pH at 25° C.:  7.7 Alkalimetric titer:   0° F.Complete alkalimetric titer:   23° F. (i.e. 4.6 meq/L) Hydrometrictiter: 28.0° F. (i.e. 134 meq/L) Lead concentration  710 micrograms perliter. Copper concentration  160 micrograms per liter. Zincconcentration  550 micrograms per liter. Magnesium concentration  3.9milligrams per liter. Calcium concentration 95.0 milligrams per liter.Strontium concentration  136 micrograms per liter. Barium concentration  17 micrograms per liter.

The water was contaminated by dissolving lead nitride to saturation andthen filtered, whereby an initial Pb²⁺ cation content of 710 microgramsper liter was obtained.

The thereby contaminated water was percolated in a bed containing 50 gof the extracting material Si2323TAM contained in a chromatographycolumn with a diameter equal to 2.5 cm, by means of a peristaltic pumphaving a flow rate of 1 L/h.

10 mL samples were regularly taken at the column outlet. Each sample wasacidified to 2% with ultra pure nitric acid, and then analyzed by atomicemission spectrometry with inductively coupled plasma (ICP-AES).

The change in the concentration of the different elements Pb, Cu, Zn,Mg, Ca, Sr, Ba is copied out in Table 1 below, wherein:

-   -   V designates the accumulated volume of taken samples (in        liters);    -   [Pb], [Cu], [Zn], [Mg], [Ca], [Sr], and [Ba] designate the        concentrations of the respective elements (in micrograms per        liter except for Mg and Ca where they are expressed in        milligrams per liter).

TABLE 1 Cation concentration at the outlet of the column [Ba] V [Pb][Cu] [Zn] [Mg] [Ca] [Sr] (μg (L) (μg L⁻¹) (μg L⁻¹) (μg L⁻¹) (mg L⁻¹) (mgL⁻¹) (μg L⁻¹) L⁻¹) 0.1 1.9 0.9 0.3 3.7 88.0 142.4 24.1 0.2 1.2 0.8 0.23.9 94.0 138.0 17.8 0.3 0.6 0.9 0.1 3.9 95.0 138.5 17.4 0.4 1.3 1.1 0.33.9 95.0 136.8 17.2 0.5 1.2 0.9 0.1 3.9 96.0 138.4 17.3 0.6 0.6 1.0 0.33.9 97.0 138.6 17.3 0.7 1.9 1.1 0.2 3.9 97.0 138.5 17.3 0.8 0.8 1.1 0.63.9 97.0 138.7 17.4 0.9 1.6 1.0 0.4 3.9 97.0 138.4 17.3 1.0 0.6 1.1 0.53.9 98.0 139.5 17.4 1.1 2.2 1.1 0.7 3.9 98.0 140.4 17.5 1.2 0.5 1.1 0.53.9 98.0 139.2 17.3 1.3 1.8 1.1 0.4 3.9 97.0 137.6 17.1 1.4 0.2 1.2 0.23.9 97.0 137.6 17.1 1.5 1.3 1.1 0.6 3.9 97.0 137.3 17.0 1.6 1.3 1.2 0.63.9 97.0 137.5 17.1 1.7 2.4 1.3 0.5 3.9 97.0 136.9 17.0 1.8 0.9 1.3 0.63.9 97.0 137.0 17.0 1.9 1.0 1.3 0.5 3.9 97.0 137.3 17.1 2.0 1.8 1.3 0.63.9 97.0 138.0 17.1 2.1 0.3 1.5 0.6 3.9 97.0 137.0 17.0 2.2 1.4 1.4 0.53.9 98.0 137.9 17.1 2.3 0.3 1.4 0.7 3.9 98.0 137.2 17.1 2.4 1.8 1.3 0.73.9 98.0 138.5 17.1 2.5 0.4 1.4 0.9 3.9 97.0 136.0 17.0 2.6 2.3 1.6 0.73.9 98.0 137.0 17.0 2.7 1.1 1.7 0.9 3.9 97.0 136.3 17.0 2.8 1.5 1.4 0.83.9 98.0 137.6 17.1 2.9 0.3 1.6 0.9 3.9 97.0 137.2 17.1 3.0 2.2 1.6 0.93.9 98.0 137.6 17.2 3.1 0.4 1.6 0.9 3.9 98.0 137.4 17.0 3.2 3.1 1.8 0.83.9 98.0 137.4 17.1 3.3 2.0 1.8 0.9 3.9 97.0 136.1 17.0 3.4 2.0 1.6 1.03.9 98.0 136.4 17.1 3.5 0.5 1.7 0.8 3.9 98.0 137.4 17.1 3.6 2.1 1.8 1.03.9 98.0 136.9 17.0 3.7 1.9 1.7 1.2 3.9 98.0 137.2 17.0 3.8 1.0 2.1 1.53.9 97.0 136.3 17.1 3.9 1.0 1.9 1.0 3.9 98.0 137.7 17.3 4.0 1.9 1.9 1.03.7 94.0 131.4 16.5 4.1 1.4 1.5 0.7 3.7 94.0 132.1 16.6 4.2 1.6 6.8 3.83.7 93.0 131.2 16.4 4.3 1.3 1.9 1.3 3.7 94.0 132.5 16.5 4.4 1.6 2.1 1.03.7 93.0 132.2 16.4

The observed results demonstrate excellent selectivity of the materialwhich does bind earth alkaline metals but efficiently retains lead,copper and zinc.

EXAMPLE 11 Example of Application of the Material Si2323ENTAM

Purification of Water of the Lead-Contaminated Drinking Water Type(Filtering Cartridge)

In this example, the material Si2323ENTAM as prepared in Example 4 wasused in a filtering cartridge of the type described for example inpatent JP 02 301469, which is attached to the outlet tap of a sink.

More specifically, the cartridge of cylindrical shape (outer diameter: 6cm; inner diameter: 5.5 cm, length: 9 cm) comprises:

-   -   a central portion (diameter: 2.5 cm) consisting of a bundle of        hollow fibers developing a surface area of about 0.1 m²; and    -   a hollow annular portion around this central portion, with a        volume of 110 mL. This annular portion is intended to receive an        extracting material, and in the present example it is filled        with the material Si2323ENTAM.

The cartridge is provided with a side inlet for the water to be treatedat the base of the annular portion and with an outlet for the treatedwater at the base of the bundle of hollow fibers of the central portion.Moreover, the high portion of the annular portion and the high portionof the central portion are in fluidic connection. Thus, the water whichpenetrates into the cartridge when the tap is opened, fills the annularportion (inflow of the water through the base improves the distributionof the fluid in the annular portion and reduces the probability of flowthrough preferential paths dug in the bed of the material), and then,having arrived in the high portion of the annular portion, the waterpasses into the central portion and flows through the bundle of hollowfibers in order to reach the outlet of the cartridge.

In the present example, several tests were carried out in whichlead-contaminated water obtained by letting drinking water stagnate for30 minutes in a lead pipe with a volume of 4.4 L connected on one sideto the drinking water supply network and on the other side to a tapprovided with the cartridge described earlier.

In each of the conducted tests, a complete purge of the pipe was firstcarried out by letting 30 L of water flow through it. The water was thenleft to stagnate in the pipe, by closing the tap for 30 minutes. Afterhaving carried out a 250 mL purge upstream and downstream from thecartridge, 2 L of water from the pipe were sampled. The flow rate of thewater exiting the cartridge in the conducted tests is 110 liters perhour.

For each of the tests, the taken 2 L sample was homogenized by stirring,and then a 10 mL sample was taken which was acidified to 2% by ultrapure nitric acid, and then analyzed by inductively coupling plasmaatomic emission spectrometry (ICP-AES).

In each case, the lead content measured in the water stemming from thetreatment with the filtering cartridge was compared with that of thewater of the first collected jet upstream from the cartridge during theinitial purge.

The results are copied out in Table 2 hereafter, wherein [Pb]_(i)designates the initial lead concentration, i.e. measured in the water ofthe first jet, and [Pb]_(f) designates the final lead concentration,i.e. measured at the outlet of the cartridge. The values of theseconcentrations are given in micrograms per liter.

TABLE 2 Reduction in the Pb concentration by passing into the filteringcartridge test 1 2 3 4 5 6 7 8 9 10 11 [Pb]_(i) 53 78 73 65 77 647 61511 541 518 53 [Pb]_(f) 9 7 5 6 6 6 7 3 4 4 5

The results above conspicuously bring out the efficiency of the materialSi2323ENTAM for retaining Pb²⁺ cations, with a very low lead content atthe output, systematically less than 10 micrograms per liter.

The invention claimed is:
 1. A material adapted for extracting metalcations in an aqueous medium, comprising polyazacycloalkane compounds(PACs) immobilized on a solid support (S), the material fitting thefollowing formula (Ia):

wherein: a, b and c are three integers, either identical or different,each of a, b and c being equal to 2 or 3; d1 and d2 are two integers,either identical or different, equal to 0, 1 or 2, it being understoodthat the sum (d1+d2) has the value 1 or 2; —Y— is a saturated orunsaturated, linear or branched divalent hydrocarbon group; j is aninteger equal to 0, 1, 2 or 3; and k, which represents the number ofbonds between the cyclic species and the solid support (S), is aninteger equal to 1, 2 or 3; and each of the 4 Rc groups, eitheridentical or different, represents a group fitting the general formula:—(CH₂)_(n)—C(═O)—NR¹R² wherein n=1, 2 or 3; and R¹ and R² are identicalof different and each of them represents a hydrogen atom or an alkylradical comprising 1 to 4 carbon atoms, or an alkenyl radical comprising1 to 4 carbon atoms or an aryl radical.
 2. The material according toclaim 1, wherein the solid support (S) comprises a mineral oxide.
 3. Amaterial adapted for extracting metal cations in an aqueous medium,comprising polyazacycloalkane compounds (PACs) immobilized on a solidsupport (S), the material fitting the following formula (II):

wherein: p=1, 2 or 3; R³ represents a hydrogen atom, or an alkyl radicalcomprising 1 to 4 carbon atoms, or an alkenyl radical comprising 1 to 4carbon atoms, or an aryl radical; and -(A)- represents a saturated orunsaturated, linear or branched hydrocarbon chain, optionallyinterrupted by one or more heteroatoms, bound by at least one covalentbond to the solid support (S); a, b, c and d are three integers, eitheridentical or different, each of a, b, c and d being equal to 2 or 3;each of the 3 Rc groups, either identical or different represents agroup fitting the general formula:—(CH₂)_(n)—C(═O)—NR¹R² wherein n=1, 2 or 3; and R¹ and R² are identicalof different and each of them represents a hydrogen atom or an alkylradical comprising 1 to 4 carbon atoms, or an alkenyl radical comprising1 to 4 carbon atoms or an aryl radical.
 4. The material according toclaim 3, wherein the solid support (S) comprises a mineral oxide.
 5. Thematerial according to claim 3, comprising the polyazacycloalkanecompounds (PACs) immobilized on the solid support (S), the materialfitting the following formula (IIa):

wherein: a, b, c, d, p and the groups Rc and R³ have the meanings givenin claim 3; z is a saturated or unsaturated, linear or branched divalenthydrocarbon group; j′ is a integer equal to 0, 1, 2 or 3; and k′, whichrepresents the number of bonds between the cyclic species and the solidsupport (S), is an integer equal to 1, 2 or
 3. 6. The material accordingto claim 5, wherein the solid support (S) comprises a mineral oxide. 7.A method for scavenging metal ions comprising contacting a liquid mediumcontaining metal cations with the material as defined in claim
 1. 8. Amethod for scavenging metal ions comprising contacting a liquid mediumcontaining metal cations with the material as defined in claim
 3. 9. Amethod for scavenging metal ions comprising contacting a liquid mediumcontaining metal cations with the material as defined in claim
 5. 10. Amethod for purifying a liquid medium contaminated with metal cationscomprising contacting the liquid medium with a material as defined inclaim
 1. 11. The method according to claim 10, wherein the metal cationsare Pb²⁺ cations.
 12. A method for purifying a liquid mediumcontaminated with metal cations comprising contacting the liquid mediumwith a material as defined in claim
 3. 13. The method according to claim12, wherein the metal cations are Pb²⁺ cations.
 14. A method forpurifying a liquid medium contaminated with metal cations comprisingcontacting the liquid medium with a material as defined in claim
 5. 15.The method according to claim 14, wherein the metal cations are Pb²⁺cations.